From c64be78ffb415278d7d32d6f55de95c73dcc19a4 Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Mon, 11 Jul 2011 16:28:50 +0200 Subject: [PATCH] sched: Fix 32bit race Commit 3fe1698b7fe0 ("sched: Deal with non-atomic min_vruntime reads on 32bit") forgot to initialize min_vruntime_copy which could lead to an infinite while loop in task_waking_fair() under some circumstances (early boot, lucky timing). [ This bug was also reported by others that blamed it on the RCU initialization problems ] Reported-and-tested-by: Bruno Wolff III Signed-off-by: Peter Zijlstra Reviewed-by: Paul E. McKenney Signed-off-by: Linus Torvalds --- kernel/sched.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/kernel/sched.c b/kernel/sched.c index 9769c756ad66..3dc716f6d8ad 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -7757,6 +7757,9 @@ static void init_cfs_rq(struct cfs_rq *cfs_rq, struct rq *rq) #endif #endif cfs_rq->min_vruntime = (u64)(-(1LL << 20)); +#ifndef CONFIG_64BIT + cfs_rq->min_vruntime_copy = cfs_rq->min_vruntime; +#endif } static void init_rt_rq(struct rt_rq *rt_rq, struct rq *rq) -- 2.30.2